The present invention relates to an image formation apparatus using an electrostatic writing method, and more particularly to an image formation apparatus using an electrostatic writing method which has a simplified structure and a shortened path for paper conveyance.
Today, according to the striking development in communications, the transmission speed of information has become surprisingly rapid and various models for visualizing the transmitted information have been presented. Along with the needs for office automation, various information transmission and reproduction apparatuses have been developed Such as telex and facsimile. Among these, image formation apparatuses for reproducing sharp images ranging from characters or symbols to figures and color pictures have become increasingly important.
Meanwhile, such image formation apparatuses are divided into electrostatic writing types and magnetic writing types. In the electrostatic writing type, a photoconductive insulating layer is electrified uniformly and is exposed to light. Then, the charges in the exposed portion are removed to form an electrostatic latent image which is then developed by electrically charged toner and transferred to paper to be fixed thereto by heat and/or pressure, thus ultimately obtaining a picture. In the magnetic writing type, as suggested by its name, a magnetic latent image is formed by a magnetic head on a magnetic drum and is developed and transferred to obtain the final picture.
FIG. 1 illustrates a conventional image formation apparatus using an electrostatic writing method. As shown in FIG. 1, a paper supply cassette 1 is installed in the lower portion of the apparatus. A transferring device 3 is placed under and adjacent to a photosensitive drum 4, and a laser scanning device 5 for protecting image information is installed in the upper portion of the apparatus. A paper supply roller 2 is provided on the top of paper supply cassette 1. Along a paper traveling path 11, register rollers 9 and 9', fixing rollers 8 and 8', paper conveyance rollers 15 and 15', and paper discharging rollers 10 and 10' are provided at specific intervals subsequent to paper supply roller 2. An electrifying device 17 is installed on the top of photosensitive drum 4 and a cleaner 13 for removing toner remaining on photosensitive drum 4 is installed under electrifying device 17.
The operation of the conventional image formation apparatus will be described below in brief.
The top sheet of paper is supplied by paper supply roller 2 from paper supply cassette 1 mounted in the lower portion of the apparatus, and is aligned and propelled by register rollers 9 and 9'. Then, image information is projected from laser scanning device 5 in the upper portion of the apparatus to the surface of photosensitive drum 4 electrified by electrifying device 17, so as to form an electrostatic latent image. Developer is applied to the electrostatic latent image from a developing device 6. Image toner 18 is transferred by transferring device 3 onto the paper conveyed by register rollers 9 and 9'. The image toner 18 transferred on the paper is compressed by fixing rollers 8 and 8' of an image fixing device 7, is conveyed by conveyance rollers 15 and 15', and is then discharged to a paper discharge tray 12 by paper discharging rollers 10 and 10' via an additional guiding device 14 for face-down discharge. Toner remaining on the surface of photosensitive drum 4 after being transferred in the transfer step is removed by cleaner 13.
However, since such a conventional image formation apparatus has an overly long paper feed path (from the paper being supplied from paper supply cassette 1 to it being loaded into paper discharge tray 12 by paper discharging rollers 10 and 10'), paper feed trouble takes place frequently, such as paper jams. Moreover, when this occurs, as the paper is pressed by a plurality of rollers, i.e., 2, 9, 9', 8, 8', 15, 15', 10, and 10', it is very difficult to remove the paper.